[HIHO1196] Gaussian elimination two (Gaussian elimination, enumeration of free elements)

Source: Internet
Author: User

Title Link: http://hihocoder.com/problemset/problem/1196

1#include <bits/stdc++.h>2 using namespacestd;3 4typedef pair<int,int>PII;5 Const intMAXN = the;6 intEquvar;7 intA[MAXN][MAXN];8 intX[MAXN];9 intFREE_X[MAXN];Ten intFree_num; One intret; A  - intGauss () { -     intMax_r, col, K; theFree_num =0; -      for(k =0, col =0; K < equ && Col <var; k++, col++) { -Max_r =K; -          for(inti = k +1; i < equ; i++) { +             if(ABS (A[i][col]) >ABS (A[max_r][col])) -Max_r =i; +         } A         if(A[max_r][col] = =0) { atk--; -free_x[free_num++] =Col; -             Continue; -         } -         if(Max_r! =k) { -              for(intj = col; J <var+1; J + +) in swap (A[k][j], a[max_r][j]); -         } to          for(inti = k +1; i < equ; i++) { +             if(A[i][col]! =0) { -                  for(intj = col; J <var+1; J + +) { theA[I][J] ^=A[k][j]; *                 } $             }Panax Notoginseng         } -     } the      for(inti = k; i < equ; i++) { +         if(A[i][col]! =0) A             return-1; the     } +     if(K <var)return var-K; -      for(inti =var-1; I >=0; i--) { $X[i] = a[i][var]; $          for(intj = i +1; J <var; J + +) { -X[i] ^= (a[i][j) &x[j]); -         } the     } -     return 0;Wuyi } the  - CharG[MAXN][MAXN]; Wu intN, M; -  About intMain () { $     //freopen ("in", "R", stdin); -m =5, n =6; -     var= Equ = -; -RET =0; AMemset (A,0,sizeof(a)); +      for(inti =0; I < n; i++) scanf ("%s", G[i]); the      for(inti =0; I < m; i++) { -          for(intj =0; J < N; J + +) { $             if(G[i][j] = ='0') a[i*n+j][var] =1; the             Elsea[i*n+j][var] =0; the         } the     } the      for(inti =0; I < -; i++) { -A[i][i] =1; in         ifI6!=0) a[i-1][i] =1; the         ifI6!=5) a[i+1][i] =1; the         if(I >5) a[i-6][i] =1; About         if(I < -) a[i+6][i] =1; the     } the     intv =Gauss (); the     if(v = =-1) ret =-1; +     Else if(V! =0) { -RET =MAXN; the         inttot =1<<v;Bayi          for(inti =0; i < tot; i++) { the             intCNT =0; the              for(intj =0; J < V; J + +) { -                 if(i& (1<<j)) { -X[FREE_X[J]] =1; thecnt++; the                 } the                 ElseX[FREE_X[J]] =0; the             } -              for(intj =var-V-1; J >=0; j--) { the                 intidx; the                  for(idx = j; idx <var; idx++) { the                     if(A[j][idx]) Break;94                 } theX[IDX] = a[j][var]; the                  for(intL = idx +1; L <var; l++) { the                     if(A[j][l]) X[idx] ^=X[l];98                 } AboutCNT + =X[idx]; -             }101RET =min (ret, CNT);102         }103     }104     Else  for(inti =0; I <var; i++) ret + =X[i]; theprintf"%d\n", ret);106Vector<pii>va;107      for(inti =0; I < -; i++) {108         if(X[i]) {109             intpos = i +1; the             intR =1, C =0;111              while(Pos >6) { thepos-=6;113r++; the             } thec + =Pos; the Va.push_back (PII (R, c));117         }118     }119 sort (Va.begin (), Va.end ()); -      for(inti =0; I < va.size (); i++) {121printf"%d%d\n", Va[i].first, va[i].second);122     }123     return 0;124}

[HIHO1196] Gaussian elimination two (Gaussian elimination, enumeration of free elements)

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